There are several synonyms for the phrase "soon to be." One option is "upcoming," which implies that something is going to happen in the very near future. Another possibility is "imminent," which has a slightly more urgent connotation and suggests that something could occur at any moment. "Forthcoming" is another alternative, indicating that something is expected and will happen in the near future. "Approaching" is yet another synonym, signifying that the event in question is rapidly approaching. Whatever the synonym used, the meaning of "soon to be" is clear: something is going to happen soon.